1. Field of the Invention
The present invention relates to an apparatus for arbitrarily aligning a semiconductor substrate, and particularly to an apparatus and method for aligning a notch or orientation flat (hereinafter referred to as xe2x80x9coriflaxe2x80x9d) provided at an edge portion of a semiconductor substrate to an arbitrary position.
2. Description of the Related Art
Conventionally, there has been used an apparatus for aligning a notch or xe2x80x9coriflaxe2x80x9d of a semiconductor substrate to an arbitrary position during conveyance of the semiconductor substrate in a semiconductor manufacturing apparatus or between semiconductor apparatuses. Normally, in such an apparatus, a vacuum suction apparatus is vacuum clung to a rear surface of a semiconductor substrate and rotates the semiconductor substrate so that a notch or xe2x80x9coriflaxe2x80x9d reaches an arbitrary position.
However, with a demand for ultra fineness and high density in a device in recent years, particle contamination of a rear surface of a semiconductor substrate has become a problem.
In the method using the vacuum suction apparatus, the rear surface of the semiconductor substrate is contaminated by the dirt of a vacuum pat, particles produced from that, reverse diffusion of particles from the vacuum suction apparatus, or the like.
An object of the present invention is therefore to provide an aligner apparatus and method in which a notch or xe2x80x9coriflaxe2x80x9d can be aligned to an arbitrary position without contaminating a rear surface of a semiconductor substrate.
Another object of the present invention is to provide an aligner apparatus and method in which alignment is quickly completed by a simple structure and an aligned semiconductor substrate can be accurately conveyed.
A device of the present invention to achieve the foregoing objects is an aligner apparatus for arbitrarily aligning a circular semiconductor substrate having a notch or xe2x80x9coriflaxe2x80x9d at an edge portion. This apparatus includes at least three spindle means rotatably axially supported by a plate, holding means for holding the semiconductor substrate, attached to respective tip ends of the spindle means, a rotation mechanism for rotating the spindle means, and a sensor for detecting the notch or xe2x80x9coriflaxe2x80x9d.
An edge portion of the semiconductor substrate is brought into contact with the respective holding means, so that the semiconductor substrate is held. When the spindle means are rotated, the semiconductor substrate held by the holding means is also rotated around its axial line.
The holding means includes a taper-shaped roller portion, so that it can quickly and certainly come in contact with the edge portion of the semiconductor substrate.
The roller portion preferably includes a guide portion of a spherical or taper shape at a tip end in its axial direction, and the semiconductor substrate can be guided to the roller portion by this guide portion.
It is desirable that the holding means is attached to the tip end of the spindle means movably only in the axial direction, and an elastic member intervenes between the holding means and the spindle means.
The rotation mechanism preferably includes a pulse motor for rotating the spindle means, and the rotation of the pulse motor is controlled by a signal from the sensor.
The sensor detects the notch or xe2x80x9coriflaxe2x80x9d of the semiconductor substrate, and transmits the signal to the pulse motor so as to rotate the semiconductor substrate until the notch or xe2x80x9coriflaxe2x80x9d reaches a predetermined position.
In a method of the present invention for arbitrarily aligning a semiconductor substrate by using the foregoing apparatus of the present invention, the semiconductor substrate is first conveyed to a position where the edge portion is brought into contact with the respective holding means. Next, the rotation mechanism is started to rotate the spindle means, and the semiconductor substrate held by the holding means is rotated around the axial line. The sensor detects the notch or xe2x80x9coriflaxe2x80x9d. On the basis of the detected signal, the spindle means is rotated by the rotation mechanism, and the semiconductor substrate is rotated to the predetermined position. In this way, alignment of the semiconductor substrate is completed.